Effect of Ni on microstructure, mechanical and high temperature property of mechanically alloyed W-Ni-Nb

The investigation comprises the synthesis of tungsten (W) based alloys with nominal composition of W70Ni20Nb10 (alloy A), W75Ni15Nb10, (alloy B) (all in wt.%) by mechanical alloying (MA) in a planetary ball mill. The milled powders are compacted at 500 MPa compaction pressure and pressureless sintering at 1500 degrees C for 2 h in Ar atmosphere. The milled powders and the consolidated products have been studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM). Minimum crystallite size and maximum lattice strain of 45 nm and 0.42% respectively is achieved in alloy B. Maximum sinterability, hardness of 90.5%, 4.44 GPa (at 50(gf)) respectively is achieved in alloy B due to finer crystallite size. Alloy Higher presence of NbNi intermetallics is evident in sintered alloy A as revealed from XRD analysis. (C) 2019 Elsevier Ltd. All rights reserved.